Bolster



March 20', 1934. o. w. SCHAUM BOLSTER Filed April 7, 1932 IN V EN TOR. aw- W BY d ' ATTORNEYS.

'Illll/Ill ll Patented Mar. 20, 1934 UNITED STATES PATENT OFFICE? 2 Claims.

This invention is directed to an improvement in bolsters for spindles, and has for some of its objects the reduction of vibration and saving in power.

A further advantage of my invention is the provision of a bolster construction embodying an oil reservoir, the reservoir having a capacity far in excess of that heretofore employed, my invention providing a construction capable of maintaining the oil in useful condition almost indefinitely.

My invention also provides a construction in which I employ a cast iron bolster and steel base, the cast iron bolster providing an excellent bearing for the spindle blade, while the steel base permits of the necessary machining, etc. and yet when finished is ideal for retaining oil. The steel base, furthermore, permits of the press fit assembling of the bolster and base without danger of splitting the base.

A still further object of my invention is the provision of a bolster which is so constructed that more uniformity of twist is obtained than with constructions used heretofore.

Yet another object of my invention is the provision of a bolster having the advantages above referred to which may be manufactured cheaply.

As is well known in the silk twisting art filled bobbins frequently run out of true and cause the spindle blade to change its position when rotated at high speeds so that it does not rotate about its geometric axis. This is likely to cause vibrations to be transmitted through the driving belt and other parts of the machine to other spindles, which is very objectionable.

When the bolsters are of rigid construction, as in usual practice in the silk twisting industry, they are mounted on a felt washer and held down by a strong spring. Such a bolster is rather heavy and when vibrated by a bobbin that is out of true two things occur. First, more power is required, as more mass is kept in motion than in a true running spindle with the same load; and second, as the point about which the spindle as a whole vibrates is just below the felt washer and therefore about two inches below the belt center, the vibration tends to jar the belt out of contact with the whorl for at least a portion of the revolution. As the belts of silk twisters are very nearly straight where they touch the whorls each of the features mentioned above tends to cause ticular spindle.

The present invention provides a construction wherein these objectionable features are entirely eliminated or much reduced; According to my invention I provide a bolster which is of fiexible material instead of rigid construction, as above mentioned, and as distinguished from cotton type constructions where the bolster is rigid (not flexible) and is loosely mounted in a base. By employing a bolster of flexible material I effect a reduction in mass of metal vibrated with a corresponding power saving. This saving in power is an important consideration where thousands of spindles are being operated. It will be appreciated also that by making the bolster of flexible material less vibration will be transmitted to the machine, this making for more uniformity in twist than in the prior spindle structures above referred to.

Saving in power and uniformity of twist are further promoted by so mounting my bolster that its upper end has a press fit in the base, the center of oscillation thus being brought opposite the belt center, so that vibration does not cause the belt to leave the whorl.

In addition to all of the foregoing I eliminate all rubbing of the bolster against the base, and although I employ an oil reservoir between the bolster and the base the rapid movement of the oil in this reservoir, so objectionable in prior devices, is eliminated. In this connection I may say that in prior devices the space or oil reservoir between the bolster and base is small compared to the movement of the bolster, only a few thousands of an inch as a matter of fact, with the result that when the bolster moves rapidly toward the base and there is nothing but a very thin film of thin oil to keep the bolster and base apart, the oil is moved at high speed between these surfaces transversely to the line of approach of the bolster to the base and heating of the oil occurs. This causes rapid deterioration of the oil, the oil becoming black and unfit for use, necessitating frequent changing. I have found also that where the bolster vibrates into rubbing contact with the base these surfaces oxidize and dirty the oil. The result of all this is the necessity of frequent oil changes.

As distinguished from such constructions I provide a bolster of flexible material and in which the space or oil reservoir between the bolster and base is large (the bolster is spaced from the base about as compared with existing structures where the space is only a few thousands of an inch and as compared to the motion of the flexing endof the bolster. In this way I provide a reservoir of extremely large capacity and also avoid rubbing of the bolster against the base. The result is such a reduction in the rapid movement of the oil above referred to as practically to amount to elimination of such movement, and the oil remains cool indefinitely. In this connection it is to be noted that present constructions necessitate oil change about every six weeks (250 to 300 working hours) while I have had my construction operating for 3600 hours and the oil is still clean. As a matter or fact throwsters estimate my construction may be run from one and a half to two years without changing the oil.

In the accompanying drawing:

Fig. 1 is a sectional elevation of an embodiment of my invention; and

Fig. 2 is a section on the line 2--2 of Fig. 1.

Referring to the drawing, 1 designates a steel spindle base having a straight internal bore and carrying a cast iron bolster 2 of my improved construction and which receives spindle blade 3. The drive pulley or whorl for the spindle blade is designated 4 and the belt is designated 5.

The bolster 2 may be said to comprise a cantilever construction in that the upper end 6 thereof for a distance not more than one-fourth of the length of the bolster, is straight sided and has a press fit in the steel base 1 to prevent tipping oi the bolster in the base, While the remainder of the bolster is reduced in outside diameter from the point 8 to the lower end 9 01 the bolster so as to be considerably smaller than the inside diameter of the bore in the base and to provide an oil reservoir of very much increased capacity as compared to existing structures. The lower end of the bolster terminates short of the bottom of the bore in the base.

It is to be noted also that the lower part of the bolster, for at least three-fourths of the length of the bolster (from the point 8 to the bottom) the bolster is of thin section-sufficiently thin to make the bolster flexible, thereby reducing the mass to be moved with a corresponding saving in power, while less vibration is transmitted to the machine. It is to be understood also that by providing for having the upper end of the bolster a press fit in the base, as above described, the center of oscillation is brought substantially opposite the center of the belt 5 so that vibration will not cause the belt to be jarred away from the whorl 4. This results in more uniform twist of the material being handled and also effects a power saving, which in twisting is a major expense. The bolster 2 provides an upper bearing '10 and lower bearing 11 for the spindle blade so that I have a construction in which the spindle blade has upper and lower bearings in a bolster, the bolster itself intermediate these bearings being of flexible material.

As above mentioned the outside diameter of the lower part of the bolster throughout at. least three-fourths of the length of the bolster, from the point 8 to the lower end of the bolster, is such as to provide an extremely large oil reservoir 12 between the base 1 and the bolster, this construction also preventing contact of the'bolster, under maximum flexing of the same, with the side walls of the bore in the base. To insure proper circulation that portion of the bolster 6 which is a press It will be seen from the foregoing that I have provided a construction in which I employ a cast iron bolster having a press flt at its upper end in a supporting steel base, the bearing or support thus provided being straight sided, and so located as to bring the center of oscillation of the bolster opposite the center of 'the belt 5, the remainder of the bolster being of flexible material and spaced sufliciently from the bore of the base to provide an extremely large oil reservoir and to prevent rubbing of the bolster against the walls of the base bore. As above noted these features reduce the transmission of vibrations to other parts 01 the machine, saves in power, produces more uniformity of twist due to reduction in tendency of the belt to leave the whorl and so reduces the rapid movement 01' the oil in the reservoir as substantially to eliminate heating, oxidizing and carbonizing of the oil, and oiling periods are reduced to the minimum.

What I claim is:

1. A spindle base, a bolster terminating within the limits of the outer end of said base, the upper terminal of said bolster having a press fit in said base, the entire bolster below said press fit being of such outside diameter relatively to the bore in the spindle base as to be maintained out of contact with the walls of said bore to provide an oil reservoir about the bolster, a spindle blade rotatable in said bolster, said bolster abreast of the portion thereof which has the fit in the spindle base providing the upper bearing for the spindle blade, the lower end of the bolster providing a step bearing for the lower end of the spindle blade; means for maintaining communication between said reservoir and the interior of said bolster, and oil channels between the said upper terminal of the bolster and the spindle base whereby oil passing upwardly of the bolster along the outside of the spindle blade will be returned to said' reservoir along the inside of the spindle base.

2. A spindle base, a bolster terminating within the limits of the outer end of said base, the upper terminal of said bolster having a press fit in said base, the entire bolster below said press fit being of such outside diameter relatively to the bore in the spindle base as to be maintained out of contact with the walls of said bore to provide an oil reservoir about the bolster, a spindle blade rotatable in said bolster, said bolster abreast of the portion thereof which has the fit in the spindle base providing the upper bearing for the spindle blade, the lower end of the bolster providing a step bearing for the lower end of the spindle blade, means for maintaining communication between said reservoir and the interior of said bolster, oil channels between the said upper terminal of the bolster and the spindle base whereby oil passing upwardly of the bolster along the outside of the spindle blade will be returned to said reservoir along the inside of the spindle base, and a whorl carried by the blade and extending downwardly around the upper end of the base preventing the entrance of foreign materials to the base.

O'I'IO W. SCHAUM.

flt in the base is provided with longitudinally extending oil grooves 13. a 

